Start of 2012, March shatter U.S. heat records

In a paper that NASA’s top climate scientist, James Hansen, submitted to the journal Proceedings of the National Academy of Sciences and posted on a physics research archive, Hansen shows that heat extremes are not just increasing but are happening far more often than scientists thought.

What used to be a 1-in-400 hot temperature record is now a 1 in 10 occurrence, essentially 40 times more likely, said Hansen. The warmth in March is an ideal illustration of this, said Hansen, who also has become an activist in fighting fossil fuels.